Bentonite, it dries super slow and shrinks like no other clay

Notes

It took more than a week for this small sample to dry. To make this thick gel I propeller-mixed a slurry as thick as I could make it and then let it sit for two weeks to evaporate off water. It would be very difficult to make it into a plastic material, but if I did the drying shrinkage would likely be 30% (typical plastic forming clays are around 5-8%!).